+++++++++++

Python News

+++++++++++

What's New in Python 3.6.1 final?

=================================

*Release date: XXXX-XX-XX*

Core and Builtins

-----------------

- bpo-29714: Fix a regression that bytes format may fail when containing zero

bytes inside.

Library

-------

- bpo-29615: SimpleXMLRPCDispatcher no longer chains KeyError (or any other

exception) to exception(s) raised in the dispatched methods.

Patch by Petr Motejlek.

What's New in Python 3.6.1 release candidate 1

==============================================

*Release date: 2017-03-04*

Core and Builtins

-----------------

- bpo-28893: Set correct __cause__ for errors about invalid awaitables

returned from __aiter__ and __anext__.

- bpo-29683: Fixes to memory allocation in _PyCode_SetExtra. Patch by

Brian Coleman.

- bpo-29684: Fix minor regression of PyEval_CallObjectWithKeywords.

It should raise TypeError when kwargs is not a dict. But it might

cause segv when args=NULL and kwargs is not a dict.

- Issue #28598: Support __rmod__ for subclasses of str being called before

str.__mod__. Patch by Martijn Pieters.

- bpo-29572: Update Windows build and OS X installers to use OpenSSL 1.0.2k.

- bpo-29607: Fix stack_effect computation for CALL_FUNCTION_EX.

Patch by Matthieu Dartiailh.

- bpo-29602: Fix incorrect handling of signed zeros in complex constructor for

complex subclasses and for inputs having a __complex__ method. Patch

by Serhiy Storchaka.

- bpo-29347: Fixed possibly dereferencing undefined pointers

when creating weakref objects.

- bpo-29438: Fixed use-after-free problem in key sharing dict.

- Issue #29319: Prevent RunMainFromImporter overwriting sys.path[0].

- Issue #29337: Fixed possible BytesWarning when compare the code objects.

Warnings could be emitted at compile time.

- Issue #29327: Fixed a crash when pass the iterable keyword argument to

sorted().

- Issue #29034: Fix memory leak and use-after-free in os module (path_converter).

- Issue #29159: Fix regression in bytes(x) when x.__index__() raises Exception.

- Issue #28932: Do not include <sys/random.h> if it does not exist.

- Issue #25677: Correct the positioning of the syntax error caret for

indented blocks. Based on patch by Michael Layzell.

- Issue #29000: Fixed bytes formatting of octals with zero padding in alternate

form.

- Issue #26919: On Android, operating system data is now always encoded/decoded

to/from UTF-8, instead of the locale encoding to avoid inconsistencies with

os.fsencode() and os.fsdecode() which are already using UTF-8.

- Issue #28991: functools.lru_cache() was susceptible to an obscure reentrancy

bug triggerable by a monkey-patched len() function.

- Issue #28739: f-string expressions are no longer accepted as docstrings and

by ast.literal_eval() even if they do not include expressions.

- Issue #28512: Fixed setting the offset attribute of SyntaxError by

PyErr_SyntaxLocationEx() and PyErr_SyntaxLocationObject().

- Issue #28918: Fix the cross compilation of xxlimited when Python has been

built with Py_DEBUG defined.

- Issue #28731: Optimize _PyDict_NewPresized() to create correct size dict.

Improve speed of dict literal with constant keys up to 30%.

Extension Modules

-----------------

- Issue #29169: Update zlib to 1.2.11.

Library

-------

- bpo-29623: Allow use of path-like object as a single argument in

ConfigParser.read(). Patch by David Ellis.

- bpo-28963: Fix out of bound iteration in asyncio.Future.remove_done_callback

implemented in C.

- bpo-29704: asyncio.subprocess.SubprocessStreamProtocol no longer closes

before all pipes are closed.

- bpo-29271: Fix Task.current_task and Task.all_tasks implemented in C

to accept None argument as their pure Python implementation.

- bpo-29703: Fix asyncio to support instantiation of new event loops

in child processes.

- bpo-29376: Fix assertion error in threading._DummyThread.is_alive().

- bpo-28624: Add a test that checks that cwd parameter of Popen() accepts

PathLike objects. Patch by Sayan Chowdhury.

- bpo-28518: Start a transaction implicitly before a DML statement.

Patch by Aviv Palivoda.

- bpo-29532: Altering a kwarg dictionary passed to functools.partial()

no longer affects a partial object after creation.

- bpo-29110: Fix file object leak in aifc.open() when file is given as a

filesystem path and is not in valid AIFF format. Patch by Anthony Zhang.

- Issue #28556: Various updates to typing module: typing.Counter, typing.ChainMap,

improved ABC caching, etc. Original PRs by Jelle Zijlstra, Ivan Levkivskyi,

Manuel Krebber, and Łukasz Langa.

- Issue #29100: Fix datetime.fromtimestamp() regression introduced in Python

3.6.0: check minimum and maximum years.

- Issue #29519: Fix weakref spewing exceptions during interpreter shutdown

when used with a rare combination of multiprocessing and custom codecs.

- Issue #29416: Prevent infinite loop in pathlib.Path.mkdir

- Issue #29444: Fixed out-of-bounds buffer access in the group() method of

the match object. Based on patch by WGH.

- Issue #29335: Fix subprocess.Popen.wait() when the child process has

exited to a stopped instead of terminated state (ex: when under ptrace).

- Issue #29290: Fix a regression in argparse that help messages would wrap at

non-breaking spaces.

- Issue #28735: Fixed the comparison of mock.MagickMock with mock.ANY.

- Issue #29316: Restore the provisional status of typing module, add

corresponding note to documentation. Patch by Ivan L.

- Issue #29219: Fixed infinite recursion in the repr of uninitialized

ctypes.CDLL instances.

- Issue #29011: Fix an important omission by adding Deque to the typing module.

- Issue #28969: Fixed race condition in C implementation of functools.lru_cache.

KeyError could be raised when cached function with full cache was

simultaneously called from differen threads with the same uncached arguments.

- Issue #29142: In urllib.request, suffixes in no_proxy environment variable with

leading dots could match related hostnames again (e.g. .b.c matches a.b.c).

Patch by Milan Oberkirch.

- Issue #28961: Fix unittest.mock._Call helper: don't ignore the name parameter

anymore. Patch written by Jiajun Huang.

- Issue #29203: functools.lru_cache() now respects PEP 468 and preserves

the order of keyword arguments. f(a=1, b=2) is now cached separately

from f(b=2, a=1) since both calls could potentially give different results.

- Issue #15812: inspect.getframeinfo() now correctly shows the first line of

a context. Patch by Sam Breese.

- Issue #29094: Offsets in a ZIP file created with extern file object and modes

"w" and "x" now are relative to the start of the file.

- Issue #29085: Allow random.Random.seed() to use high quality OS randomness

rather than the pid and time.

- Issue #29061: Fixed bug in secrets.randbelow() which would hang when given

a negative input. Patch by Brendan Donegan.

- Issue #29079: Prevent infinite loop in pathlib.resolve() on Windows

- Issue #13051: Fixed recursion errors in large or resized

curses.textpad.Textbox. Based on patch by Tycho Andersen.

- Issue #29119: Fix weakrefs in the pure python version of

collections.OrderedDict move_to_end() method.

Contributed by Andra Bogildea.

- Issue #9770: curses.ascii predicates now work correctly with negative

integers.

- Issue #28427: old keys should not remove new values from

WeakValueDictionary when collecting from another thread.

- Issue 28923: Remove editor artifacts from Tix.py.

- Issue #29055: Neaten-up empty population error on random.choice()

by suppressing the upstream exception.

- Issue #28871: Fixed a crash when deallocate deep ElementTree.

- Issue #19542: Fix bugs in WeakValueDictionary.setdefault() and

WeakValueDictionary.pop() when a GC collection happens in another

thread.

- Issue #20191: Fixed a crash in resource.prlimit() when passing a sequence that

doesn't own its elements as limits.

- Issue #28779: multiprocessing.set_forkserver_preload() would crash the

forkserver process if a preloaded module instantiated some

multiprocessing objects such as locks.

- Issue #28847: dbm.dumb now supports reading read-only files and no longer

writes the index file when it is not changed.

- Issue #26937: The chown() method of the tarfile.TarFile class does not fail

now when the grp module cannot be imported, as for example on Android

platforms.

Windows

-------

- bpo-29579: Removes readme.txt from the installer

- Issue #29326: Ignores blank lines in ._pth files (Patch by Alexey Izbyshev)

- Issue #28164: Correctly handle special console filenames (patch by Eryk Sun)

- Issue #29409: Implement PEP 529 for io.FileIO (Patch by Eryk Sun)

- Issue #29392: Prevent crash when passing invalid arguments into msvcrt module.

- Issue #25778: winreg does not truncate string correctly (Patch by Eryk Sun)

- Issue #28896: Deprecate WindowsRegistryFinder and disable it by default.

C API

-----

- Issue #27867: Function PySlice_GetIndicesEx() is replaced with a macro if

Py_LIMITED_API is not set or set to the value between 0x03050400

and 0x03060000 (not including) or 0x03060100 or higher.

- Issue #29083: Fixed the declaration of some public API functions.

PyArg_VaParse() and PyArg_VaParseTupleAndKeywords() were not available in

limited API. PyArg_ValidateKeywordArguments(), PyArg_UnpackTuple() and

Py_BuildValue() were not available in limited API of version < 3.3 when

PY_SSIZE_T_CLEAN is defined.

- Issue #29058: All stable API extensions added after Python 3.2 are now

available only when Py_LIMITED_API is set to the PY_VERSION_HEX value of

the minimum Python version supporting this API.

Documentation

-------------

- bpo-28929: Link the documentation to its source file on GitHub.

- bpo-25008: Document smtpd.py as effectively deprecated and add a pointer to

aiosmtpd, a third-party asyncio-based replacement.

- Issue #26355: Add canonical header link on each page to corresponding major

version of the documentation. Patch by Matthias Bussonnier.

- Issue #29349: Fix Python 2 syntax in code for building the documentation.

Tests

-----

- bpo-28087: Skip test_asyncore and test_eintr poll failures on macOS.

Skip some tests of select.poll when running on macOS due to unresolved

issues with the underlying system poll function on some macOS versions.

- Issue #29571: to match the behaviour of the ``re.LOCALE`` flag,

test_re.test_locale_flag now uses ``locale.getpreferredencoding(False)`` to

determine the candidate encoding for the test regex (allowing it to correctly

skip the test when the default locale encoding is a multi-byte encoding)

- Issue #28950: Disallow -j0 to be combined with -T/-l in regrtest

command line arguments.

- Issue #28683: Fix the tests that bind() a unix socket and raise

PermissionError on Android for a non-root user.

- Issue #26939: Add the support.setswitchinterval() function to fix

test_functools hanging on the Android armv7 qemu emulator.

Build

-----

- bpo-27593: sys.version and the platform module python_build(),

python_branch(), and python_revision() functions now use

git information rather than hg when building from a repo.

- bpo-29572: Update Windows build and OS X installers to use OpenSSL 1.0.2k.

- Issue #26851: Set Android compilation and link flags.

- Issue #28768: Fix implicit declaration of function _setmode. Patch by

Masayuki Yamamoto

- Issue #29080: Removes hard dependency on hg.exe from PCBuild/build.bat

- Issue #23903: Added missed names to PC/python3.def.

- Issue #28762: lockf() is available on Android API level 24, but the F_LOCK

macro is not defined in android-ndk-r13.

- Issue #28538: Fix the compilation error that occurs because if_nameindex() is

available on Android API level 24, but the if_nameindex structure is not

defined.

- Issue #20211: Do not add the directory for installing C header files and the

directory for installing object code libraries to the cross compilation

search paths. Original patch by Thomas Petazzoni.

- Issue #28849: Do not define sys.implementation._multiarch on Android.

What's New in Python 3.6.0?

===========================

*Release date: 2016-12-23*

- No changes since release candidate 2

What's New in Python 3.6.0 release candidate 2?

===============================================

*Release date: 2016-12-16*

Core and Builtins

-----------------

- Issue #28147: Fix a memory leak in split-table dictionaries: setattr()

must not convert combined table into split table. Patch written by INADA

Naoki.

- Issue #28990: Fix asyncio SSL hanging if connection is closed before

handshake is completed. (Patch by HoHo-Ho)

Tools/Demos

-----------

- Issue #28770: Fix python-gdb.py for fastcalls.

Windows

-------

- Issue #28896: Deprecate WindowsRegistryFinder.

Build

-----

- Issue #28898: Prevent gdb build errors due to HAVE_LONG_LONG redefinition.

What's New in Python 3.6.0 release candidate 1?

===============================================

*Release date: 2016-12-06*

Core and Builtins

-----------------

- Issue #23722: Rather than silently producing a class that doesn't support

zero-argument ``super()`` in methods, failing to pass the new

``__classcell__`` namespace entry up to ``type.__new__`` now results in a

``DeprecationWarning`` and a class that supports zero-argument ``super()``.

- Issue #28797: Modifying the class __dict__ inside the __set_name__ method of

a descriptor that is used inside that class no longer prevents calling the

__set_name__ method of other descriptors.

- Issue #28782: Fix a bug in the implementation ``yield from`` when checking

if the next instruction is YIELD_FROM. Regression introduced by WORDCODE

(issue #26647).

Library

-------

- Issue #27030: Unknown escapes in re.sub() replacement template are allowed

again. But they still are deprecated and will be disabled in 3.7.

- Issue #28835: Fix a regression introduced in warnings.catch_warnings():

call warnings.showwarning() if it was overriden inside the context manager.

- Issue #27172: To assist with upgrades from 2.7, the previously documented

deprecation of ``inspect.getfullargspec()`` has been reversed. This decision

may be revisited again after the Python 2.7 branch is no longer officially

supported.

- Issue #26273: Add new :data:`socket.TCP_CONGESTION` (Linux 2.6.13) and

:data:`socket.TCP_USER_TIMEOUT` (Linux 2.6.37) constants. Patch written by

Omar Sandoval.

- Issue #24142: Reading a corrupt config file left configparser in an

invalid state. Original patch by Florian Höch.

- Issue #28843: Fix asyncio C Task to handle exceptions __traceback__.

C API

-----

- Issue #28808: PyUnicode_CompareWithASCIIString() now never raises exceptions.

Documentation

-------------

- Issue #23722: The data model reference and the porting section in the What's

New guide now cover the additional ``__classcell__`` handling needed for

custom metaclasses to fully support PEP 487 and zero-argument ``super()``.

Tools/Demos

-----------

- Issue #28023: Fix python-gdb.py didn't support new dict implementation.

What's New in Python 3.6.0 beta 4?

==================================

*Release date: 2016-11-21*

Core and Builtins

-----------------

- Issue #28532: Show sys.version when -V option is supplied twice.

- Issue #27100: The with-statement now checks for __enter__ before it

checks for __exit__. This gives less confusing error messages when

both methods are missing. Patch by Jonathan Ellington.

- Issue #28746: Fix the set_inheritable() file descriptor method on platforms

that do not have the ioctl FIOCLEX and FIONCLEX commands.

- Issue #26920: Fix not getting the locale's charset upon initializing the

interpreter, on platforms that do not have langinfo.

- Issue #28648: Fixed crash in Py_DecodeLocale() in debug build on Mac OS X

when decode astral characters. Patch by Xiang Zhang.

- Issue #19398: Extra slash no longer added to sys.path components in case of

empty compile-time PYTHONPATH components.

- Issue #28665: Improve speed of the STORE_DEREF opcode by 40%.

- Issue #28583: PyDict_SetDefault didn't combine split table when needed.

Patch by Xiang Zhang.

- Issue #27243: Change PendingDeprecationWarning -> DeprecationWarning.

As it was agreed in the issue, __aiter__ returning an awaitable

should result in PendingDeprecationWarning in 3.5 and in

DeprecationWarning in 3.6.

- Issue #26182: Fix a refleak in code that raises DeprecationWarning.

- Issue #28721: Fix asynchronous generators aclose() and athrow() to

handle StopAsyncIteration propagation properly.

Library

-------

- Issue #28752: Restored the __reduce__() methods of datetime objects.

- Issue #28727: Regular expression patterns, _sre.SRE_Pattern objects created

by re.compile(), become comparable (only x==y and x!=y operators). This

change should fix the issue #18383: don't duplicate warning filters when the

warnings module is reloaded (thing usually only done in unit tests).

- Issue #20572: The subprocess.Popen.wait method's undocumented

endtime parameter now raises a DeprecationWarning.

- Issue #25659: In ctypes, prevent a crash calling the from_buffer() and

from_buffer_copy() methods on abstract classes like Array.

- Issue #19717: Makes Path.resolve() succeed on paths that do not exist.

Patch by Vajrasky Kok

- Issue #28563: Fixed possible DoS and arbitrary code execution when handle

plural form selections in the gettext module. The expression parser now

supports exact syntax supported by GNU gettext.

- Issue #28387: Fixed possible crash in _io.TextIOWrapper deallocator when

the garbage collector is invoked in other thread. Based on patch by

Sebastian Cufre.

- Issue #28600: Optimize loop.call_soon.

- Issue #28613: Fix get_event_loop() return the current loop if

called from coroutines/callbacks.

- Issue #28634: Fix asyncio.isfuture() to support unittest.Mock.

- Issue #26081: Fix refleak in _asyncio.Future.__iter__().throw.

- Issue #28639: Fix inspect.isawaitable to always return bool

Patch by Justin Mayfield.

- Issue #28652: Make loop methods reject socket kinds they do not support.

- Issue #28653: Fix a refleak in functools.lru_cache.

- Issue #28703: Fix asyncio.iscoroutinefunction to handle Mock objects.

- Issue #28704: Fix create_unix_server to support Path-like objects

(PEP 519).

- Issue #28720: Add collections.abc.AsyncGenerator.

Documentation

-------------

- Issue #28513: Documented command-line interface of zipfile.

Tests

-----

- Issue #28666: Now test.support.rmtree is able to remove unwritable or

unreadable directories.

- Issue #23839: Various caches now are cleared before running every test file.

Build

-----

- Issue #10656: Fix out-of-tree building on AIX. Patch by Tristan Carel and

Michael Haubenwallner.

- Issue #26359: Rename --with-optimiations to --enable-optimizations.

- Issue #28676: Prevent missing 'getentropy' declaration warning on macOS.

Patch by Gareth Rees.

What's New in Python 3.6.0 beta 3?

==================================

*Release date: 2016-10-31*

Core and Builtins

-----------------

- Issue #28128: Deprecation warning for invalid str and byte escape

sequences now prints better information about where the error

occurs. Patch by Serhiy Storchaka and Eric Smith.

- Issue #28509: dict.update() no longer allocate unnecessary large memory.

- Issue #28426: Fixed potential crash in PyUnicode_AsDecodedObject() in debug

build.

- Issue #28517: Fixed of-by-one error in the peephole optimizer that caused

keeping unreachable code.

- Issue #28214: Improved exception reporting for problematic __set_name__

attributes.

- Issue #23782: Fixed possible memory leak in _PyTraceback_Add() and exception

loss in PyTraceBack_Here().

- Issue #28471: Fix "Python memory allocator called without holding the GIL"

crash in socket.setblocking.

Library

-------

- Issue #27517: LZMA compressor and decompressor no longer raise exceptions if

given empty data twice. Patch by Benjamin Fogle.

- Issue #28549: Fixed segfault in curses's addch() with ncurses6.

- Issue #28449: tarfile.open() with mode "r" or "r:" now tries to open a tar

file with compression before trying to open it without compression. Otherwise

it had 50% chance failed with ignore_zeros=True.

- Issue #23262: The webbrowser module now supports Firefox 36+ and derived

browsers. Based on patch by Oleg Broytman.

- Issue #27939: Fixed bugs in tkinter.ttk.LabeledScale and tkinter.Scale caused

by representing the scale as float value internally in Tk. tkinter.IntVar

now works if float value is set to underlying Tk variable.

- Issue #18844: The various ways of specifying weights for random.choices()

now produce the same result sequences.

- Issue #28255: calendar.TextCalendar().prmonth() no longer prints a space

at the start of new line after printing a month's calendar. Patch by

Xiang Zhang.

- Issue #20491: The textwrap.TextWrapper class now honors non-breaking spaces.

Based on patch by Kaarle Ritvanen.

- Issue #28353: os.fwalk() no longer fails on broken links.

- Issue #28430: Fix iterator of C implemented asyncio.Future doesn't accept

non-None value is passed to it.send(val).

- Issue #27025: Generated names for Tkinter widgets now start by the "!" prefix

for readability (was "`").

- Issue #25464: Fixed HList.header_exists() in tkinter.tix module by addin

a workaround to Tix library bug.

- Issue #28488: shutil.make_archive() no longer adds entry "./" to ZIP archive.

- Issue #25953: re.sub() now raises an error for invalid numerical group

reference in replacement template even if the pattern is not found in

the string. Error message for invalid group reference now includes the

group index and the position of the reference.

Based on patch by SilentGhost.

- Issue #18219: Optimize csv.DictWriter for large number of columns.

Patch by Mariatta Wijaya.

- Issue #28448: Fix C implemented asyncio.Future didn't work on Windows.

- Issue #28480: Fix error building socket module when multithreading is

disabled.

- Issue #24452: Make webbrowser support Chrome on Mac OS X.

- Issue #20766: Fix references leaked by pdb in the handling of SIGINT

handlers.

- Issue #28492: Fix how StopIteration exception is raised in _asyncio.Future.

- Issue #28500: Fix asyncio to handle async gens GC from another thread.

- Issue #26923: Fix asyncio.Gather to refuse being cancelled once all

children are done.

Patch by Johannes Ebke.

- Issue #26796: Don't configure the number of workers for default

threadpool executor.

Initial patch by Hans Lawrenz.

- Issue #28544: Implement asyncio.Task in C.

Windows

-------

- Issue #28522: Fixes mishandled buffer reallocation in getpathp.c

Build

-----

- Issue #28444: Fix missing extensions modules when cross compiling.

- Issue #28208: Update Windows build and OS X installers to use SQLite 3.14.2.

- Issue #28248: Update Windows build and OS X installers to use OpenSSL 1.0.2j.

Tests

-----

- Issue #26944: Fix test_posix for Android where 'id -G' is entirely wrong or

missing the effective gid.

- Issue #28409: regrtest: fix the parser of command line arguments.

What's New in Python 3.6.0 beta 2?

==================================

*Release date: 2016-10-10*

Core and Builtins

-----------------

- Issue #28183: Optimize and cleanup dict iteration.

- Issue #26081: Added C implementation of asyncio.Future.

Original patch by Yury Selivanov.

- Issue #28379: Added sanity checks and tests for PyUnicode_CopyCharacters().

Patch by Xiang Zhang.

- Issue #28376: The type of long range iterator is now registered as Iterator.

Patch by Oren Milman.

- Issue #28376: Creating instances of range_iterator by calling range_iterator

type now is deprecated. Patch by Oren Milman.

- Issue #28376: The constructor of range_iterator now checks that step is not 0.

Patch by Oren Milman.

- Issue #26906: Resolving special methods of uninitialized type now causes

implicit initialization of the type instead of a fail.

- Issue #18287: PyType_Ready() now checks that tp_name is not NULL.

Original patch by Niklas Koep.

- Issue #24098: Fixed possible crash when AST is changed in process of

compiling it.

- Issue #28201: Dict reduces possibility of 2nd conflict in hash table when

hashes have same lower bits.

- Issue #28350: String constants with null character no longer interned.

- Issue #26617: Fix crash when GC runs during weakref callbacks.

- Issue #27942: String constants now interned recursively in tuples and frozensets.

- Issue #21578: Fixed misleading error message when ImportError called with

invalid keyword args.

- Issue #28203: Fix incorrect type in complex(1.0, {2:3}) error message.

Patch by Soumya Sharma.

- Issue #28086: Single var-positional argument of tuple subtype was passed

unscathed to the C-defined function. Now it is converted to exact tuple.

- Issue #28214: Now __set_name__ is looked up on the class instead of the

instance.

- Issue #27955: Fallback on reading /dev/urandom device when the getrandom()

syscall fails with EPERM, for example when blocked by SECCOMP.

- Issue #28192: Don't import readline in isolated mode.

- Upgrade internal unicode databases to Unicode version 9.0.0.

- Issue #28131: Fix a regression in zipimport's compile_source(). zipimport

should use the same optimization level as the interpreter.

- Issue #28126: Replace Py_MEMCPY with memcpy(). Visual Studio can properly

optimize memcpy().

- Issue #28120: Fix dict.pop() for splitted dictionary when trying to remove a

"pending key" (Not yet inserted in split-table). Patch by Xiang Zhang.

- Issue #26182: Raise DeprecationWarning when async and await keywords are

used as variable/attribute/class/function name.

Library

-------

- Issue #27998: Fixed bytes path support in os.scandir() on Windows.

Patch by Eryk Sun.

- Issue #28317: The disassembler now decodes FORMAT_VALUE argument.

- Issue #26293: Fixed writing ZIP files that starts not from the start of the

file. Offsets in ZIP file now are relative to the start of the archive in

conforming to the specification.

- Issue #28380: unittest.mock Mock autospec functions now properly support

assert_called, assert_not_called, and assert_called_once.

- Issue #27181 remove statistics.geometric_mean and defer until 3.7.

- Issue #28229: lzma module now supports pathlib.

- Issue #28321: Fixed writing non-BMP characters with binary format in plistlib.

- Issue #28225: bz2 module now supports pathlib. Initial patch by Ethan Furman.

- Issue #28227: gzip now supports pathlib. Patch by Ethan Furman.

- Issue #27358: Optimized merging var-keyword arguments and improved error

message when passing a non-mapping as a var-keyword argument.

- Issue #28257: Improved error message when passing a non-iterable as

a var-positional argument. Added opcode BUILD_TUPLE_UNPACK_WITH_CALL.

- Issue #28322: Fixed possible crashes when unpickle itertools objects from

incorrect pickle data. Based on patch by John Leitch.

- Issue #28228: imghdr now supports pathlib.

- Issue #28226: compileall now supports pathlib.

- Issue #28314: Fix function declaration (C flags) for the getiterator() method

of xml.etree.ElementTree.Element.

- Issue #28148: Stop using localtime() and gmtime() in the time

module.

Introduced platform independent _PyTime_localtime API that is

similar to POSIX localtime_r, but available on all platforms. Patch

by Ed Schouten.

- Issue #28253: Fixed calendar functions for extreme months: 0001-01

and 9999-12.

Methods itermonthdays() and itermonthdays2() are reimplemented so

that they don't call itermonthdates() which can cause datetime.date

under/overflow.

- Issue #28275: Fixed possible use after free in the decompress()

methods of the LZMADecompressor and BZ2Decompressor classes.

Original patch by John Leitch.

- Issue #27897: Fixed possible crash in sqlite3.Connection.create_collation()

if pass invalid string-like object as a name. Patch by Xiang Zhang.

- Issue #18844: random.choices() now has k as a keyword-only argument

to improve the readability of common cases and come into line

with the signature used in other languages.

- Issue #18893: Fix invalid exception handling in Lib/ctypes/macholib/dyld.py.

Patch by Madison May.

- Issue #27611: Fixed support of default root window in the tkinter.tix module.

Added the master parameter in the DisplayStyle constructor.

- Issue #27348: In the traceback module, restore the formatting of exception

messages like "Exception: None". This fixes a regression introduced in

3.5a2.

- Issue #25651: Allow falsy values to be used for msg parameter of subTest().

- Issue #27778: Fix a memory leak in os.getrandom() when the getrandom() is

interrupted by a signal and a signal handler raises a Python exception.

- Issue #28200: Fix memory leak on Windows in the os module (fix

path_converter() function).

- Issue #25400: RobotFileParser now correctly returns default values for

crawl_delay and request_rate. Initial patch by Peter Wirtz.

- Issue #27932: Prevent memory leak in win32_ver().

- Fix UnboundLocalError in socket._sendfile_use_sendfile.

- Issue #28075: Check for ERROR_ACCESS_DENIED in Windows implementation of

os.stat(). Patch by Eryk Sun.

- Issue #22493: Warning message emitted by using inline flags in the middle of

regular expression now contains a (truncated) regex pattern.

Patch by Tim Graham.

- Issue #25270: Prevent codecs.escape_encode() from raising SystemError when

an empty bytestring is passed.

- Issue #28181: Get antigravity over HTTPS. Patch by Kaartic Sivaraam.

- Issue #25895: Enable WebSocket URL schemes in urllib.parse.urljoin.

Patch by Gergely Imreh and Markus Holtermann.

- Issue #28114: Fix a crash in parse_envlist() when env contains byte strings.

Patch by Eryk Sun.

- Issue #27599: Fixed buffer overrun in binascii.b2a_qp() and binascii.a2b_qp().

- Issue #27906: Fix socket accept exhaustion during high TCP traffic.

Patch by Kevin Conway.

- Issue #28174: Handle when SO_REUSEPORT isn't properly supported.

Patch by Seth Michael Larson.

- Issue #26654: Inspect functools.partial in asyncio.Handle.__repr__.

Patch by iceboy.

- Issue #26909: Fix slow pipes IO in asyncio.

Patch by INADA Naoki.

- Issue #28176: Fix callbacks race in asyncio.SelectorLoop.sock_connect.

- Issue #27759: Fix selectors incorrectly retain invalid file descriptors.

Patch by Mark Williams.

- Issue #28368: Refuse monitoring processes if the child watcher has no

loop attached.

Patch by Vincent Michel.

- Issue #28369: Raise RuntimeError when transport's FD is used with

add_reader, add_writer, etc.

- Issue #28370: Speedup asyncio.StreamReader.readexactly.

Patch by Коренберг Марк.

- Issue #28371: Deprecate passing asyncio.Handles to run_in_executor.

- Issue #28372: Fix asyncio to support formatting of non-python coroutines.

- Issue #28399: Remove UNIX socket from FS before binding.

Patch by Коренберг Марк.

- Issue #27972: Prohibit Tasks to await on themselves.

Windows

-------

- Issue #28402: Adds signed catalog files for stdlib on Windows.

- Issue #28333: Enables Unicode for ps1/ps2 and input() prompts. (Patch by

Eryk Sun)

- Issue #28251: Improvements to help manuals on Windows.

- Issue #28110: launcher.msi has different product codes between 32-bit and

64-bit

- Issue #28161: Opening CON for write access fails

- Issue #28162: WindowsConsoleIO readall() fails if first line starts with

Ctrl+Z

- Issue #28163: WindowsConsoleIO fileno() passes wrong flags to

_open_osfhandle

- Issue #28164: _PyIO_get_console_type fails for various paths

- Issue #28137: Renames Windows path file to ._pth

- Issue #28138: Windows ._pth file should allow import site

C API

-----

- Issue #28426: Deprecated undocumented functions PyUnicode_AsEncodedObject(),

PyUnicode_AsDecodedObject(), PyUnicode_AsDecodedUnicode() and

PyUnicode_AsEncodedUnicode().

Build

-----

- Issue #28258: Fixed build with Estonian locale (python-config and distclean

targets in Makefile). Patch by Arfrever Frehtes Taifersar Arahesis.

- Issue #26661: setup.py now detects system libffi with multiarch wrapper.

- Issue #15819: Remove redundant include search directory option for building

outside the source tree.

Tests

-----

- Issue #28217: Adds _testconsole module to test console input.

What's New in Python 3.6.0 beta 1?

==================================

*Release date: 2016-09-12*

Core and Builtins

-----------------

- Issue #23722: The __class__ cell used by zero-argument super() is now

initialized from type.__new__ rather than __build_class__, so class methods

relying on that will now work correctly when called from metaclass methods

during class creation. Patch by Martin Teichmann.

- Issue #25221: Fix corrupted result from PyLong_FromLong(0) when Python

is compiled with NSMALLPOSINTS = 0.

- Issue #27080: Implement formatting support for PEP 515. Initial patch

by Chris Angelico.

- Issue #27199: In tarfile, expose copyfileobj bufsize to improve throughput.

Patch by Jason Fried.

- Issue #27948: In f-strings, only allow backslashes inside the braces

(where the expressions are). This is a breaking change from the 3.6

alpha releases, where backslashes are allowed anywhere in an

f-string. Also, require that expressions inside f-strings be

enclosed within literal braces, and not escapes like

f'\x7b"hi"\x7d'.

- Issue #28046: Remove platform-specific directories from sys.path.

- Issue #28071: Add early-out for differencing from an empty set.

- Issue #25758: Prevents zipimport from unnecessarily encoding a filename

(patch by Eryk Sun)

- Issue #25856: The __module__ attribute of extension classes and functions

now is interned. This leads to more compact pickle data with protocol 4.

- Issue #27213: Rework CALL_FUNCTION* opcodes to produce shorter and more

efficient bytecode. Patch by Demur Rumed, design by Serhiy Storchaka,

reviewed by Serhiy Storchaka and Victor Stinner.

- Issue #26331: Implement tokenizing support for PEP 515. Patch by Georg Brandl.

- Issue #27999: Make "global after use" a SyntaxError, and ditto for nonlocal.

Patch by Ivan Levkivskyi.

- Issue #28003: Implement PEP 525 -- Asynchronous Generators.

- Issue #27985: Implement PEP 526 -- Syntax for Variable Annotations.

Patch by Ivan Levkivskyi.